ubiquinone and nicotinamide-hypoxanthine-dinucleotide

ubiquinone has been researched along with nicotinamide-hypoxanthine-dinucleotide* in 2 studies

Other Studies

2 other study(ies) available for ubiquinone and nicotinamide-hypoxanthine-dinucleotide

Article	Year
Enzymatic and energetic properties of the aerobic respiratory chain-linked NADH oxidase system in the marine bacterium Pseudomonas nautica. Molecules and cells, 2000, Aug-31, Volume: 10, Issue:4 Membranes of Pseudomonas nautica, grown aerobically on a complex medium, oxidized both NADH and deamino-NADH as substrates. The activity of membrane-bound NADH oxidase was activated by monovalent cations including Na+, Li+, and K+. The activation by Na+ was higher than that by Li+ and K+. The maximum activity of NADH oxidase was obtained at about pH 9.0 in the presence of 0.08 M NaCl. The NADH oxidase activity was completely inhibited by 60 microM 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO), while the NADH:quinone oxidoreductase activity was about 37% inhibited by 60 microM HQNO. The activities of NADH oxidase and NADH:quinone oxidoreductase were about 40% inhibited by 60 microM rotenone. The fluorescence quenching technique revealed that electron transfer from NADH to ubiquinone-1 (Q-1) or oxygen generated a membrane potential (deltapsi) which was larger and more stable in the presence of Na+ than in the absence of Na+. However, the All was highly sensitive to a protonophore, carbonyl-cyanide m-chlorophenylhydrazone (CCCP) even at alkaline pH. Topics: Bacterial Proteins; Electron Transport; Hydrogen-Ion Concentration; Hydroxyquinolines; Membrane Potentials; Membrane Proteins; Multienzyme Complexes; NAD; NADH, NADPH Oxidoreductases; Oxygen; Potassium Cyanide; Pseudomonas; Quinone Reductases; Rotenone; Salts; Ubiquinone; Uncoupling Agents	2000
Matrix NADH dehydrogenases of plant mitochondria and sites of quinone reduction by complex I. European journal of biochemistry, 1992, Sep-01, Volume: 208, Issue:2 In order to distinguish the pathways involved in the oxidation of matrix NADH in plant mitochondria, the oxidation of NADH and nicotinamide hypoxanthine dinucleotide (reduced form) was investigated in submitochondrial particles prepared from beetroot (Beta vulgaris L. cv. Derwent Globe) and soybeans (Glycine max L. cv. Bragg). Nicotinamide-hypoxanthine-dinucleotide(reduced form)-oxidase activity was more strongly inhibited by rotenone than the NADH-oxidase activity but both of the rotenone-inhibited activities could be stimulated by adding ubiquinone-1. The corresponding ubiquinone-1-reductase activities were inhibited by rotenone (to 69%) and further inhibited by N,N'-dicyclohexylcarbodiimide (to 79%), whilst the K3Fe(CN)6-reductase activities were not sensitive to either rotenone or N,N'-dicyclohexylcarbodiimide. Immunological analysis of mitochondrial proteins using an antiserum raised against purified beetroot complex I indicated very few differences between soybean and fresh and aged beetroot mitochondria, despite their varying sensitivities to rotenone. We confirm that there are two dehydrogenases capable of oxidising internal NADH and that only one of these, namely complex I, is inhibited by rotenone. Further, we conclude that complex I has two potential sites of quinone reduction, both sensitive to N,N'-dicyclohexycarbodiimide inhibition but only one of which is sensitive to rotenone inhibition. Topics: Benzoquinones; Dicyclohexylcarbodiimide; Glycine max; NAD; NAD(P)H Dehydrogenase (Quinone); NADH Dehydrogenase; Oxidation-Reduction; Plants; Rotenone; Submitochondrial Particles; Ubiquinone	1992

Article

Year

Enzymatic and energetic properties of the aerobic respiratory chain-linked NADH oxidase system in the marine bacterium Pseudomonas nautica.

Molecules and cells, 2000, Aug-31, Volume: 10, Issue:4

Membranes of Pseudomonas nautica, grown aerobically on a complex medium, oxidized both NADH and deamino-NADH as substrates. The activity of membrane-bound NADH oxidase was activated by monovalent cations including Na+, Li+, and K+. The activation by Na+ was higher than that by Li+ and K+. The maximum activity of NADH oxidase was obtained at about pH 9.0 in the presence of 0.08 M NaCl. The NADH oxidase activity was completely inhibited by 60 microM 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO), while the NADH:quinone oxidoreductase activity was about 37% inhibited by 60 microM HQNO. The activities of NADH oxidase and NADH:quinone oxidoreductase were about 40% inhibited by 60 microM rotenone. The fluorescence quenching technique revealed that electron transfer from NADH to ubiquinone-1 (Q-1) or oxygen generated a membrane potential (deltapsi) which was larger and more stable in the presence of Na+ than in the absence of Na+. However, the All was highly sensitive to a protonophore, carbonyl-cyanide m-chlorophenylhydrazone (CCCP) even at alkaline pH.

Topics: Bacterial Proteins; Electron Transport; Hydrogen-Ion Concentration; Hydroxyquinolines; Membrane Potentials; Membrane Proteins; Multienzyme Complexes; NAD; NADH, NADPH Oxidoreductases; Oxygen; Potassium Cyanide; Pseudomonas; Quinone Reductases; Rotenone; Salts; Ubiquinone; Uncoupling Agents

2000

Matrix NADH dehydrogenases of plant mitochondria and sites of quinone reduction by complex I.

European journal of biochemistry, 1992, Sep-01, Volume: 208, Issue:2

In order to distinguish the pathways involved in the oxidation of matrix NADH in plant mitochondria, the oxidation of NADH and nicotinamide hypoxanthine dinucleotide (reduced form) was investigated in submitochondrial particles prepared from beetroot (Beta vulgaris L. cv. Derwent Globe) and soybeans (Glycine max L. cv. Bragg). Nicotinamide-hypoxanthine-dinucleotide(reduced form)-oxidase activity was more strongly inhibited by rotenone than the NADH-oxidase activity but both of the rotenone-inhibited activities could be stimulated by adding ubiquinone-1. The corresponding ubiquinone-1-reductase activities were inhibited by rotenone (to 69%) and further inhibited by N,N'-dicyclohexylcarbodiimide (to 79%), whilst the K3Fe(CN)6-reductase activities were not sensitive to either rotenone or N,N'-dicyclohexylcarbodiimide. Immunological analysis of mitochondrial proteins using an antiserum raised against purified beetroot complex I indicated very few differences between soybean and fresh and aged beetroot mitochondria, despite their varying sensitivities to rotenone. We confirm that there are two dehydrogenases capable of oxidising internal NADH and that only one of these, namely complex I, is inhibited by rotenone. Further, we conclude that complex I has two potential sites of quinone reduction, both sensitive to N,N'-dicyclohexycarbodiimide inhibition but only one of which is sensitive to rotenone inhibition.

Topics: Benzoquinones; Dicyclohexylcarbodiimide; Glycine max; NAD; NAD(P)H Dehydrogenase (Quinone); NADH Dehydrogenase; Oxidation-Reduction; Plants; Rotenone; Submitochondrial Particles; Ubiquinone

1992